Synergistic microbiocidal composition containing a mixture of a N-alkyldimethylbenzyl ammonium halide and a bicyclicpolyoxymethylene oxazolidine

ABSTRACT

A synergistic microbiocide comprising a member selected from the group consisting of (1) an N-alkyl (C 8  -C 30 ) dimethylbenzylammonium halide and (2) a polycondensation product of acrolein/formaldehyde in a molar ratio of 1:10-10:1 in combination with (3) a bicyclic polyoxymethylene-oxaazolidine having the formula: ##STR1## in which each R represents hydrogen, an alkyl of 1-6 carbons, phenyl, halophenyl or --(CH 2  O) m  CH 2  OH in which m is 0-2 and n is 0-4, the ratio of (1) or (2) to (3) being 1:10-10:1 by weight.

This application is a continuation-in-part of application Ser. No.894,265 filed Aug. 6, 1986 now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to inhibiting the growth of bacteria invarious industrial environments. More particularly, the presentinvention relates to an improved microbiocidal composition and itsmethod of use. Still more particularly, the present invention relates toa synergistic microbiocidal composition, and its method of use, thecomposition comprising a combination of (1) an N-alkyldimethylbenzylammonium halide, or (2) a polycondensation product of acrolein andformaldehyde, and (3) a bicyclic polyoxymethyleneoxazolidine.

2. Description of the Prior Art

The presence of organic materials in the manufacture and/or use ofvarious aqueous systems such as latices, adhesives, paints, coatings,mineral slurries and the like renders them susceptible to deteriorationby virtue of exposure to bacteria and other microorganisms existing inthe particular environment. It is, therefore, a conventional practice toseek to inhibit the microbial deterioration of such systems byincorporating therein any of various materials or combinations ofmaterials that are characterized by having antibacterial activity.

Numerous materials have been found to possess such antibacterialactivity. For instance, various quaternary ammonium salts having thisactivity are disclosed in U.S. Pat. No. 4,479,820; variousacrolein/formaldehyde polycondensation products are disclosed in U.S.Pat. No. 4,501,668; and various polyoxymethyleneoxazolidines aredisclosed in U.S. Pat. No. 4,135,945. In addition, U.S. Pat. Nos.3,231,509 and 4,173,643 disclose microbiocidal synergistic combinationscomprising quaternary ammonium salts with respectively,bis(halomethyl)sulfones and 4-isothiazoline-3-ones.

SUMMARY OF THE INVENTION

It is a principal object of this invention to provide an improvedmicrobiocidal composition. It is a further object of this invention toprovide an improved microbiocidal composition that is storage stable,and which is compatible with a variety of systems susceptible tobiocidal degeneration thereby permitting its use without objectionableand/or unacceptable by-product odor, discoloration, thickening and thelike. A further object of this invention is to provide an improvedmicrobiocidal composition that is cost effective, i.e., performseffectively on the basis of its cost per unit weight and duration of itseffectiveness on the treated system. Another object of this invention isto provide an improved method of inhibiting bacterial growth in avariety of systems in industry and commerce.

DESCRIPTION OF THE PREFERRED EMBODIMENT

These objects have been met in accordance with this invention by acomposition comprising (1) an N-alkyldimethylbenzylammonium halide inwhich the alkyl has a carbon chain length of C₈ to C₃₀, or (2) anacrolein/formaldehyde condensation product having a molar ratio between1:1 and 1:10, in combination with (3) a bicyclicpolyoxymethyleneoxazolidine having the formula: ##STR2## in which each Rrepresents hydrogen, an alkyl of 1-6 carbons, phenyl, halophenyl or--(CH₂ O)_(m) CH₂ OH in which m is 0-2 and n is 0-4.

Preferably, the quaternary ammonium salt (Component 1) is an N-longchain alkyl (C₁₂ : 40; C₁₄ : 50%; C₁₆ : 10%) dimethylbenzyl ammoniumchloride obtained commercially under the trademark Hyamine®3500 fromLonza, Inc.

The acrolein/formaldehyde condensation product (Component 2) is producedby the condensation of acrolein and formaldehyde in a preferred molarratio of 1:2 to 1:4 in an aqueous or aqueous/organic medium in thepresence of a basic catalyst. Such a polycondensation product isavailable commercially under the trademark Formac®40 from Degussa.

The preferred bicyclic polyoxymethyleneoxazolidine (Component 3) is amixture comprising:

(a) 35% 5-hydroxymethyl-1-aza-3,7-dioxabicyclo(3.3.0)-octane,

(b) 48% 5-hydroxymethoxymethyl-1-aza-3,7-dioxabicyclo-(3.3.0)-octane,and

(c) 16% 5-hydroxymethyl poly[oxymethylene(C₂ : 74%; C₃ : 21%; C₄ : 4%;C₅ : 1)]-1-aza-3,7-dioxa-bicyclo-(3.3.0)-octane.

The preferred bicyclic polyoxymethyleneoxazolidine is availablecommercially under the trademark Nuosept 95 from Nuodex®, Inc.

In the practice of the invention, the quaternary ammonium salt or thepolycondensation product is used in combination with the bicyclicpolyoxymethyleneoxazolidine in a range of 1:10-10:1 by weight,preferably in a ratio range of 1:3-3:1. The composition can be employedin the form of a dilute aqueous or non-aqueous solution and can be addedto the aqueous system to be treated in any conventional way in an amounteffective to inhibit microorganic growth. Generally, the effectiveconcentration will range from as little as 100 ppm to as much as 5000ppm depending upon the nature of the system being treated. In general, aconcentration on the order of 500-2000 ppm will be found adequate.

In order to demonstrate the synergistic microbiocidal activity of thecompositions of this invention, the following Example was conducted. Allparts are by weight unless otherwise noted.

EXAMPLE

An unpreserved sample of styrene-butadiene-vinylidene chloride (SBVC)latex was analyzed for microbial content before being utilized forpreservation evaluation according to this invention. It was determinedthat the latex sample was free of contamination.

The uncontaminated, unprotected SBVC latex was divided into 50 gr.aliquots and dosed with the microbiocide compositions of this inventionas reported in the following Table. Each of the components of each ofthe compositions was also separately tested as microbiocides while twoaliquots remained untreated to serve as controls.

The challenged inoculum was a pooled suspension of microorganismscomprising the bacteria species Pseudomonas, Bacillus and Penicilliumthat had been grown from contaminated latex material. All of the sampleswere challenged on a weekly basis for 4 weeks with 0.01 ml. of thepooled suspension containing at least 10⁶ organisms per ml. Following 72hours of room temperature incubation, a 1 ml. quantity of each samplewas transferred to 2 ml. of tryptic soy broth (TSB). The TSB tubes wereincubated at room temperature for 24 hours and streaked onto TGE platesfor growth of bacteria. After 48 hours incubation at room temperature,the plates were read and graded according to the description followingthe Table.

The tested compositions comprised combinations of Component 1/Component3 and combinations of Component 2/Component 3. Component 1 was obtainedcommercially under the trademark Hyamine®3500 as an aqueous solutioncontaining 80% active ingredient. Component 2 was obtained commerciallyunder the trademark Formac®40 as an aqueous solution containing 40%active ingredient. Component 3 was obtained commercially under thetrademark Nuosept®95 as an aqueous solution containing 50% activeingredient. The compositions according to this invention as well as theseparately tested components were adjusted to an active ingredientcontent of 20%. Results appear in the following Table.

                  TABLE                                                           ______________________________________                                                       Weekly Growth Rate*                                            Biocide  Ratio   PPM     1     2     3     4                                  ______________________________________                                        Components                                                                             1:3      500    --    --    +2    +2                                 1 and 3          1000    --    --    --    --                                                  2000    --    --    --    --                                          1:1      500    --    --    --    +2                                                  1000    --    --    --    +1                                                  2000    --    --    --    --                                          3:1      500    +1    +2    +4    +4                                                  1000    --    --    --    +3                                                  2000    --    --    --    --                                 Components                                                                             1:3      500    --    +1    +1    +1                                 2 and 3          1000    --    --    --    --                                                  2000    --    --    --    --                                          1:1      500    --    +1    +1    +1                                                  1000    --    +1    +1    +1                                                  2000    --    --    --    --                                          3:1      500    --    --    --    --                                                  1000    --    --    --    --                                                  2000    --    --    --    --                                 Component 1       500    +4    +4    +4    +4                                                  1000    +4    +4    +4    +4                                                  2000    +4    +4    +4    +4                                 Component 2       500    +1    +1    +1    +2                                                  1000    --    +1    +1    +1                                                  2000    --    +1    +1    +1                                 Component 3       500    +1    +1    +1    +2                                                  1000    --    +1    +1    +2                                                  2000    --    +1    +1    +1                                 Control #1               +2    +4    +4    +4                                 Control #2               +4    +4    +4    +4                                 ______________________________________                                        *The rating system for microbial growth on streaked,                          prepoured agar plates is as follows:                                          Growth rate   Description                                                     --            No growth; zero colonies                                        +1            Maximum of 15 total colonies with                                             no more than 5 of these having                                                diameters of 1/8 inch                                           +2            Sporadic growth on 1/2 total                                                  streaked area, remaining 1/2 area                                             relatively clear; maximum of 20                                               total colonies with no more than                                              6 of these having diameters                                                   greater than 1/8 inch                                           +3            Dense growth on 2/3-3/4 of                                                    streaked area; minor colonies too                                             numerous to count; 20 or more                                                 major colonies having diameters                                               of 1/8 inch or larger                                           +4            Uniform, dense growth over entire                                             streaked area; colonies pinhead                                               size or larger                                              

Reference in the disclosure to details of specific embodiments is notintended to restrict the scope of the appended claims, which themselvesrecite those features regarded as essential to the invention.

We claim:
 1. A microbiocidal composition comprising a synergisticmixture the first component of which is N-alkyl (C₁₂ : 40%; C₁₄ : 50%;C₁₆ : 10%) dimethylbenzyl ammonium chloride and the second component ofwhich is a bicyclic polyoxymethyleneoxazolidine comprising a mixture of(a) 35% 5-hydroxymethyl-1-aza-3,7-dioxabicyclo-(3.3.0)-octane, (b) 49%5-hydroxymethoxymethyl-1-aza-3,7-dioxabicyclo(3.3.0)-octane, and (c) 16%5-hydroxymethylpoly[oxymethylene(C₂ : 74%; C₃ : 21%; C₄ : 4%; C₅ :1%)]-1-aza-3,7-dioxabicyclo(3.3.0)-octane, said first and secondcomponents being in a ratio of 1:3-3:1 by weight.
 2. A method forinhibiting the growth of bacteria in an aqueous system which comprisesadding to said system an amount of a microbiocidal composition accordingto claim 1 effective to inhibit the growth of bacteria.